How do I put my dining room into Get Menu?

Settings → Tables & QR ordering, then the Add table form. Three things for each table: what staff call it (12, Terrace 3), where it is (Inside, Terrace, Roof) and how many seats. Add them one at a time; there is no limit on how many you can have. The words you type in Where it is become the parts of your floor, so keep them short and use the same ones every time.